Automated manufacturing method and system and in-mold coated plastic article produced thereby

ABSTRACT

An automated manufacturing method and system and in-mold coated plastic article produced thereby are provided. The system includes a combination compression and injection mold and a plurality of program-controlled manipulators. An automatic sprayer supported on a first manipulator sprays at least a portion of a mold surface with an in-mold coating composition. An end effector supported on a second manipulator picks up a heated blank of moldable plastic sheet material from an oven and places the heated blank in the mold. An inner portion of the heated blank is forced into an article-defining cavity of the mold and into contact with at least a portion of the composition. The composition and the inner portion cure and bond to one another and a plastic compatible with the plastic of the sheet is injected into the mold so as to form the coated plastic article.

TECHNICAL FIELD

This invention relates to automated manufacturing methods and systemsand in-mold coated plastic articles produced thereby.

OVERVIEW

Compression molding has long been used to manufacture plastic parts orarticles. While widely used to manufacture thermoset plastic parts,compression molding is also used to manufacture thermoplastic parts orarticles. The raw materials for compression molding are typically placedin an open, heated, mold cavity. The mold is then closed and pressure isapplied to force the materials to fill up the entire cavity. A hydraulicram or punch is often utilized to produce sufficient force during themolding process. The heat and pressure are maintained until the plasticmaterials are cured.

Two types of plastic compounds frequently used in compression moldingare Bulk Molding Compound (BMC) and Sheet Molding Compound (SMC).

In general, compression molding provides good surface finish and can beapplied to composite thermoplastics with woven fabrics, randomlyoriented fiber mat or chopped strand. Compression molding is thought tobe largely limited to flat or moderately curved parts with no undercuts.

Thermoplastic matrices are commonplace in mass production industriese.g. automotive applications where the leading technologies are LongFibre reinforced Thermoplastics (LFT) and Glass fiber Mat reinforcedThermoplastics (GMT).

Driven by a growing demand by industry, governmental regulatory agenciesand consumers for durable and inexpensive products that are functionallycomparable or superior to metal products, a continuing need exists forimprovements in composite articles subjected to difficult serviceconditions. This is particularly true in the automotive industries wheredevelopers and manufacturers of articles for automotive applicationsmust meet a number of competing performance specifications for sucharticles.

For example, automotive interior parts exposed to direct sunlight, suchas instrument panels, front and rear pillar trims, parcel shelves orpackage trays under or around the front and the back windshield, tend toexperience extremely high surface heating when such vehicles are parkedin non-shaded areas and during the summer months in many parts of theworld. The exposed surfaces of the automotive interior parts are knownto reach temperatures in excess of 100° C., especially in tropical andequatorial regions of the world. Many automobile OEMs have specifiedstringent performance requirements to address the durability ofautomotive interior parts exposed to such high service temperatures.

In an effort to address these demands, a number of composite materialshave been developed, including glass mat thermoplastic (GMT) composites.GMT composites provide a number of advantages, e.g., they can be moldedand formed into a variety of suitable products both structural andnon-structural, including, among many others, automotive bumpers,interior headliners, and interior and exterior trim parts. Thetraditional GMT used in exterior structural application are generallycompression flow molded and are substantially void free in their finalpart shape.

Low density GMT (LD-GMT) used in the interior trim applications aregenerally semi-structural in nature and are porous and light weight withdensities ranging from 0.1 to 1.8 g/cm³ and containing 5% to 95% voidsdistributed uniformly through the thickness of the finished part.

Problems associated with the prior art is that prior art, mass-produced,injection molded or vacuum formed parts are heavy, suffer fromappearance problems and don't have desirable acoustic properties.

Many molded parts are used in the interior of vehicles. The substrate ofthe part is often made of plastic or preferably of a fibrous moldingmaterial.

Natural fiber composite panels utilized as a substrate have veryimportant characteristics because of their light weight and highenvironmental sustainability.

As described in U.S. patent publication Nos. 2014/0342119 and2015/0027622, the substrate of the molded part may be realized in alaminar fashion and has an essentially plane contour or athree-dimensional contour with convex and concave regions defined by therespective design, as well as, if applicable, one or more openings andrecesses for trim strips and control elements such as pushbuttons,switches and rotary knobs for power windows and exterior rearviewmirrors. In order to fix the molded parts in the passenger compartmentor on the vehicle door and to mount handles, control elements andstorage trays on the molded part, the molded part is also equipped withmounting parts that are also referred to as retainers.

The substrate typically consists of plastics or composite materials thatcontain plastics such as acrylonitrile-butadiene-styrene (ABS) orpolypropylene (PP). Fibrous molding materials on the basis of textilefabrics of hemp, sisal, flax, kenaf and/or wood components such as woodfibers, wood dust, wood chips or paper bound with duroplastic bindersare likewise used as material for the substrate. Foamed materials ofpolyurethane or epoxy resins that, if applicable, are reinforced withnatural fibers or glass fibers may also be considered as material forthe substrate.

As described in U.S. patent publication No. 2015/0027622, an interiorcovering part is produced which comprises a substrate or a carrier partcomponent and a decorative film or a decorative layer. For producing theinterior covering part, a substrate of fiber molding material, inparticular, a natural fiber molding material, and a decorative film or adecorative layer are formed in two steps, wherein these are pressedtogether in a first step of the two steps and in particular hot-pressed.

As starting material or semi-finished product for a substrate, which isused for producing the carrier component, a fiber molding material inthe form of a plastic mat with fiber components and especially apolypropylene (PP)-bound fiber mat with natural fibers and/or plasticfibers, a polypropylene (PP)-bound fiber mat with ceramic, carbon orglass fibers is used especially. This (substrate) can be plasticisable,in particular, through the supply of heat. When using a polypropylene(PP)-bound fiber mat as substrate, this preferentially comprises amaterial component of a fiber material, which is preferentially formedof natural fibers or glass fibers as well as plastic or carbon fibersand, in particular, with polypropylene (PP)-fibers (binding function).Alternatively or additionally natural fiber PP (NFPP) or glass fiber PPcan be used as fiber mat. As natural fibers, fibers of wood, kenaf,hemp, jute, flax, china grass, rattan, soya, ocra, banana, bamboo,coconut, coir, cotton, curaua, abaca, pine, pineapple, raffia palmand/or sisal can be used. Synthetic fibers can also be used. Chips ofwood can also be used as starting material for the carrier material. Assynthetic fibers, carbon fibers, fibers of polyester, acrylate, aramide,Twaron, Kevlar, Technora, vinylon, Cylon and/or polypropylene can beused. A combination of a plurality of types of the mentioned naturalfibers or other fibers can also be used in the substrate. As part of thepresent invention, the term “polymers” comprises both homopolymers aswell as copolymers of the mentioned polymer types

U.S. patent publication No. 2013/0052412 discloses a vehicular trimcomponent made by concurrent compression forming and injection molding.

The side of the respective molded part or substrate that faces thevehicle interior is usually referred to as the visible side. In order toprovide the visible side with an attractive appearance, the substrate isequipped with one or more decorative elements of a textile material or aplastic film. The plastic films used for this purpose are usuallycolored and have a relief-like embossed surface. If applicable, thedecorative elements comprise a cushioning layer of a foamed plastic thatfaces the substrate and provides the molded part with pleasantly softhaptics. The decorative elements are usually laminated onto thesubstrate or bonded thereto during the manufacture of the substrate bymeans of thermoplastic back-injection molding.

On its edge and/or on an installation side that lies opposite of thevisible side, the substrate is advantageously equipped with projections,depressions and bores. The projections, depressions and bores serve fornon-positively connecting the molded part to sections of the car bodysuch as a car door or the roof of a passenger compartment by means ofretaining elements such as clips, pins and screws.

The respective mounting parts or retainers are made of plastic or ametallic material such as sheet steel and mechanically connected to thesubstrate by means of retaining elements such as pins, screws or clipsor by means of interlacing, clawing or clamping. Retainersadvantageously comprise claws and/or clips as integral components. Theclaws and clips are respectively provided for engaging into recesses ofthe substrate or for being bent around the edge of the substrate, aswell as for being fixed by means of clamping, during the installation ofthe retainers.

Different methods that typically comprise two or more production stepsare known for the manufacture of molded parts for the interior trim ofvehicles.

According to one known method, a substrate is initially produced of afibrous molding material by means of hot-pressing. Subsequently,retainers are attached to the installation side of the substrate, e.g.,by means of friction welding or bonding. In a third step, one or moredecorative elements are laminated onto the visible side of thesubstrate. In a simplified two-step variation of the method, retainersof a metallic material with integrated retaining elements, particularlywith claws, are compressed together with the fibrous molding material,wherein the retaining elements penetrate into the fibrous moldingmaterial and non-positively anchor the retainers on the substrate afterthe fibrous molding material has cured.

According to another known method, a substrate is manufactured of athermoplastic by means of injection molding, particularly by means ofback-injection molding. One or more decorative elements are preferablyarranged in a back-injection mold and back-injected with the thermallyplasticized plastic. After the molten plastic has cooled and solidified,the decorative elements are non-positively bonded to the substrate. Inanother step, mounting parts or retainers are respectively mounted onthe installation side of the substrate.

One example of a surface texture is disclosed in WO 2010/080967 A1,according to which an interior trim panel of fibrous molding material isequipped with a smooth, transparent, liquid-impermeable,scratch-resistant and UV-resistant coating of a material, preferably athermoplastic polymer, with a melting point in the range of 60° to 170°C. The coating is applied by means of hot-pressing, wherein the materialof the coating partially sinks into the fibrous molding material suchthat the coating is non-positively connected to the fibrous moldingmaterial.

As described in U.S. Pat. No. 5,462,421 and U.S. patent publication No.2004/0150127, current vehicle inner door panels comprise laminates ofvarious types. In some inner door panels, a structural backing materialis covered by an embossed covering, which is often vinyl. These panelsare formed by bonding the covering to the backing in a mold whichembosses the covering. Sometimes a filler material, such as cellulose ora foam sheet, is bonded between the backing and covering. After bonding,the periphery of these panels must be trimmed before vehicleinstallation. In the past, this trimming has been usually accomplishedin a separate trim fixture.

The industry has developed a mold apparatus wherein the laminate isformed in a mold that also includes external trimming knives thatprovide a finished panel ready for vehicle installation. Such apparatusis shown in U.S. Pat. No. 4,692,108 to Cesano. All of the materials usedin forming the Cesano type of laminated panel are preformed.

Another type of inner door panel in use is a laminate comprising astructural substrate of reinforced foam covered by a vinyl covering.This type of laminate is formed by placing the vinyl and reinforcingmaterial in a mold and thereafter injecting foamable materials, whichexpand, set up and cure in the mold. After curing, this unfinishedlaminate requires further processing before it is ready for vehicleinstallation. It is removed from the mold and transferred to a trimfixture, where it is finally trimmed by accurately cutting the peripherywith a water jet or the like.

Some problems attend this post-formation trimming operation. Forexample, the unfinished panel must be accurately positioned in thefixture. If it is not, the final panel will be out of dimension andunusable. Such a panel must be scrapped. Also, this post-formationtrimming operation requires additional handling, equipment and labor.

U.S. Pat. No. 8,833,829 and 2012/0091698 disclose polymer skin/foambilaminate sheets. These all-olefin sheets are low cost, low weight,recyclable sheets which can be formed into vehicle interior components.

The term “facing material” refers to a material used to conceal and/orprotect structural and/or functional elements from an observer. Commonexamples of facing materials include upholstery, carpeting, and wallcoverings (including stationary and/or movable wall coverings andcubicle wall coverings). Facing materials typically provide a degree ofaesthetic appearance and/or feel, but they may also provide a degree ofphysical protection to the elements that they conceal. In someapplications, it is desirable that the facing material provideproperties such as, for example, aesthetic appeal (for example, visualappearance and/or feel) and abrasion resistance. Facing materials arewidely used in motor vehicle construction.

In the automotive industry, it is common practice to refer to varioussurfaces as being A-, B-, or C-surfaces. As used herein, the term“A-surface” refers to an outwardly-facing surface for display in theinterior of a motor vehicle. This surface is a very high visibilitysurface of the vehicle that is most important to the observer or that ismost obvious to the direct line of vision. With respect to motor vehicleinteriors, examples include dashboards, door panels, instrument panels,steering wheels, head rests, upper seat portions, headliners, loadfloors and pillar coverings. Examples are shown in FIG. 1 .

As described in U.S. patent publication 2014/0225296, one problemassociated with one method of making a panel of sandwich-type compositestructure is that during the cold-pressing in a compression mold one orboth of the skins does not fully contact or achieve abutting engagementwith its respective mold half or die during the molding process.Consequently, the resulting compression-molded, composite componentfails to achieve the desired component shape, as defined by the opposingsurfaces of upper and lower dies.

The following U.S. patent documents are related to at least oneembodiment of the present invention: U.S. Pat. Nos. 5,324,384;5,352,397; 5,370,521; 5,502,930; 5,506,029; 5,614,285; 5,718,791;5,746,870; 5,915,445; 6,050,630; 6,102,464; 6,435,577; 6,537,413;6,544,449; 6,655,299; 6,682,675; 6,682,676; 6,695,998; 6,748,876;6,790,026; 6,823,803; 6,843,525; 6,890,023; 6,981,863; 7,090,274;7,419,713; 7,909,379; 7,919,031; 8,117,972; 10,166,704; 10,279,512;10,532,499; 2003/0194542; 2005/0189674; 2006/0255611; 2008/0185866;2011/0281076; 2011/0315310; 2013/0260112; 2013/0273191; and2015/0321396.

The following U.S. patent documents are also related to at least oneembodiment of the present invention: 2014/0077518; 2014/0077530;2014/0077531; 2015/0130220; 2015/0130221; 2015/0130221; and2017/0043687.

In-mold coatings were used in the late 1980s for automotiveapplications, specifically window encapsulations and steering wheels.They used an aliphatic urethane foam substrate with a solvent-bornelacquer or two-component urethane. With the advent of lower-costaromatic elastomers in the late 1990s, a higher emphasis has been placedon converting interior automotive parts from PVC to in-moldapplications, which increases throughput and improves appearance.Currently, the following components are being prepared using in-moldprocesses: instrument panels, door panels, steering wheels, airbagcovers, armrests, assist handles, headrests and seat covers (see FIG. 1). The in-mold processes used are polyurethane sprayable elastomer,injected polyurethane elastomer and polyurethane foam. Most of theseapplications utilize waterborne in-mold coatings.

The in-mold process allows for a quicker processing time and takes upless space than a post-paint application. Most post-paint applicationsrequire between 40 and 60 minutes to process and require power washequipment, spray lines and ovens. The plastic in these applicationsrequires cleaning, degreasing and priming before it can be painted witha topcoat. Even with this extensive preparation, defects are very commonand costly to the finisher. Post-paint applications require skill andfinesse to properly apply the coatings, and still surface defects suchas picture framing, sagging, orange peel, craters and dirt contaminationcommonly occur. The post-paint process also requires that ovens bemaintained at proper temperatures to appropriately cure the post-paintfinish; a delicate and energy-intensive proposition.

The mold-in process allows for parts to be molded and coated in aone-step process so that finishers do not have to use multiple steps tomold and paint the part. This eliminates many plastic preparation costs(cleaning, degreasing, priming, sanding, flame treating, etc.) and usesless packing and shipping, less labor, and produces less waste, therebygenerating a substantial cost savings for the finisher.

The cycle time to produce a steering wheel or instrument panel (IP) skinwith an in-mold coating can range from three and a half to five minutes,depending on the mold temperature and the type of elastomer. The partand the in-mold coating are fully cured and chemically bonded to oneanother during the molding process, eliminating the need for bake ovensas in post-painted parts.

With an in-mold paint application, the visible coating surface willappear as an exact replica of the mold tool. Therefore, by using thisapplication, defects such as picture framing, sagging, cratering andorange peel are inherently eliminated. As long as the mold surface isclean and the equipment settings for the mold temperature are correct,the in-mold coating will dry shortly after as it comes in contact withthe tool.

Waterborne in-mold coatings allow for the use of lower-VOC coating dueto the application of the coating to a hot tool. Typical solvents usedfor coalescence and appearance control during the curing process are notnecessary. The VOCs of the waterborne in-mold coatings can range from0.4-1.8 lb/gal, depending on the type of coating. A flexible waterbornein-mold coating will contain 0.4-0.7 lb/gal VOC, while a soft,“leather-like-feel” two-component coating will run in the 0.8-1.8 lb/galVOC range. Post-paint waterborne coatings can range from 1.2-2.8 lb/galVOC.

The primary concerns when using in-mold coatings are flash time and acondition known as “Wet IMC.” Wet IMC happens when blistering anddelamination occur between the coating and the substrate. This conditioncan arise from short flash time, high DFT or poor application. Wet IMCmost generally occurs when the coating is applied too heavily in asingle pass. Solvent becomes trapped in the coating, which results inblistering and poor adhesion between the substrate and the paint film.This can be corrected by first selecting equipment that will properlyatomize the coating, and then using multiple passes to slowly build tothe desired DFT, thus eliminating issues associated with wet IMC.

It is common to see pinholes and imperfections in post-paintapplications when evaluating the film closely under magnification. Asstated earlier, in-mold coatings do not utilize low levels of coalescingsolvents. In an in-mold application, slow solvents are ineffective atcoalescing and facilitating flow-out over a hot tool because the coatinghits the mold and dries almost immediately on contact, resulting in verylittle flow. The excellent film quality is achieved then, not by thetypical flow and coalescing manner but by applying the coating withmultiple passes and good atomization so that the paint film is uniformand free of blisters and pinholes.

Listed below is a step-by-step process description for producing afinished part by the above-noted in-mold process.

Polyurethane Spray Skin (Instrument Panel)

1. The mold is heated and kept at a constant temperature of 160+/−5° F.through water circulation.

2. Mold release is applied (15-30 sec.) followed by a 10-30 sec. flash.The mold release can be semi-permanent or sacrificial (onerelease/application). Sacrificial-type release may be preferred due toease of release, low gloss and part-to-part gloss consistency.

3. Coating is applied at 0.8-1.5 mils to the top and bottom of the tool(60 sec.), followed by a 10-60 sec. flash.

4. Two-component polyurethane (PU) elastomer is applied to the tool atapproximately 1.0 mm thickness (60 sec.).

5. The skin is allowed to cure in the tool for 60 sec. prior todemolding.

6. The skin is prepared for the next station (backing).

In addition to processing advantages, in-mold coatings offer otheradvantages over post-painting. Complex part designs can be processedwithout the worry of part shrinkage, gloss control or marring. Thein-mold process with aromatic polyurethane allows the designer tointegrate multiple components in the part. This can be a one-piecesteering wheel/airbag unit, or an integrated passenger side airbag onspray PU IPs. The parts produced from the in-mold process yield exactduplication of the grain, finish and styling detail of the mold. Thereis no loss in shape or shrink-back after de-molding due to the fullyrelaxed state of the polymer in the finished, cured skin. The skin isformed in its desired shape at the time of molding. There is no formingor stretching of the skin, which occurs in the competing process ofthermoforming. The thermoforming process causes stretching of thematerial, which results in a loss of grain definition. It changes thesurface tension, which can lead to adhesion problems for the post-paint.Also, delamination often occurs over time due to shrink-back.

Most post-paint applications can only achieve low gloss levels byoverloading the coating with inorganic fillers. This results in adegradation of film properties such as the coating mar resistance. Within-mold coatings the tool grain and finish can be manipulated to achievea wide range of gloss levels. It is possible to achieve a 1-2 gloss bytool/finish design and mold release selection. No manipulation of thein-mold coating by addition of flattening agents or texturing agents isnecessary to achieve the desired gloss.

The texture or grain of the mold dictates the gloss of the final coatingfilm. The smoother or more polished the mold, the higher the gloss ofthe coating. For an in-mold application, the amount of flatting agentused has virtually no effect on the gloss. However, the amount offlatting agent has a major effect on the gloss with a post-paint system.The mold release used in an in-mold system can also have a minor effecton the final gloss of the coating.

The mold release used can affect the final gloss of the coating by asmuch as 5°. The polymer choice for the coating has an effect on thecoating gloss and the control of that gloss over different textured orgrained surfaces.

The in-mold process is also much better suited for two-tone applicationsthan post-paint applications. With in-mold processes, applying twocolors can be performed in the initial painting step with only a slightincrease in the processing time.

The following U.S. patents assigned to Red Spot Paint and Varnish Co.Inc. of Evansville, Ind., disclose various in-mold coated products suchas vehicular components, in-mold coating methods, and in-mold coatingcompositions, involving the use of aqueous acrylic copolymerdispersions, desirably self-crosslinking: U.S. Pat. Nos. 9,296,130;8,986,593; 9,539,745; and 10,144,157.

SUMMARY

An object of at least one embodiment of the present invention is toprovide an automated manufacturing method and system and high quality,in-mold coated plastic articles produced thereby wherein the articleslook like painted injection molded articles and wherein cycle time andlabor costs are reduced.

In carrying out the above object and other objects of at least oneembodiment of the present invention, an automated method ofmanufacturing a coated plastic article is provided. The method includesthe steps of providing a mold for making the article. The mold has upperand lower mold halves. One of the mold halves has a mold surface whichat least partially defines an article-defining cavity. The method alsoincludes coating at least a portion of the mold surface with an in-moldcoating composition and placing a heated blank of moldable plastic sheetmaterial between the upper and lower mold halves. The blank has innerand outer surfaces. The method further includes forcing an inner portionof the heated blank into the article-defining cavity so that the outersurface of the blank is in contact with at least a portion of thein-mold coating composition. Then the in-mold coating composition andthe inner portion of the blank are caused to cure and bond to oneanother. Then a plastic compatible with the plastic of the sheet ismolded to form at least one component on the inner surface of the sheetso as to form the coated plastic article.

The plastic sheet material may be a composite plastic sheet material.

The coating may have a textured, class “A” surface.

The step of forcing may be performed in a single stamping stage.

The composite plastic sheet material may comprise a plurality of fibersdispersed within a thermoplastic resin.

The thermoplastic resin may be selected from polyolefins, thermoplasticpolyolefin blends, polyvinyl polymers, diene polymers, polyamides,polyesters, polycarbonates, polyestercarbonates, styrene-containingpolymers, acrylic polymers, polyimides, polylphenylene either,polyphenylene oxide, polyphenylene sulphide, polyethers,polyetherketones, polyacetals, polyurethanes, polybenzimidazole, andcopolymers or mixtures thereof.

The fibers may be selected from glass fibers, carbon fibers, syntheticorganic fibers, natural fibers, mineral fibers, metal and/or metalizedor coated fibers, or mixtures thereof.

The article may be a decorative, automotive, interior trim article.

The fiber content may be from about 20% to about 80% by weight of thethermoplastic resin.

The article may have a thickness in a range of 1 mm to 10 mm.

Further in carrying out the above object and other objects of at leastone embodiment of the present invention, an automated system formanufacturing a coated plastic article is provided. The system includesa combination compression and injection mold having open and closedpositions for making the article. The mold has upper and lower moldhalves. One of the mold halves has a mold surface which at leastpartially defines an article-defining cavity. The system also includes aprogram-controlled first manipulator and an automatic sprayer supportedon the first manipulator for movement relative to at least two controlaxes for spraying at least a portion of the mold surface with an in-moldcoating composition. The system further includes a program-controlledsecond manipulator and an end effector supported on the secondmanipulator for movement relative to at least two control axes forpicking a heated blank of moldable plastic sheet material from an ovenand placing the heated blank between the upper and lower mold halves.The other one of the mold halves forces an inner portion of the heatedblank into the article-defining cavity and into contact with at least aportion of the in-mold coating composition. The mold halves cause thein-mold coating composition and the inner portion of the blank to cureand bond to one another in the closed position of the mold. A plasticcompatible with the plastic of the sheet is injected into thearticle-defining cavity to form at least one component on the outersurface of the sheet and so as to form the coated plastic article in theclosed position of the mold.

Each of the manipulators may be a robot.

Still further in carrying out the above object and other objects of atleast one embodiment of the invention, an in-mold coated plastic articleis provided. The article includes a rigid, molded substrate ofcompression-moldable, plastic sheet material. The substrate has innerand outer surfaces. A coating is adhered to the outer surface of thesubstrate. The coating is formed in-mold with the substrate. The atleast one component is adhered to the inner surface of the substrate.The at least one component is formed in-mold with the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view, partially broken away, of an automotive interiorwherein possible locations of a decorative interior trim partconstructed in accordance with at least one embodiment of the presentinvention are indicated by arrows 100;

FIG. 2 is a front perspective view of a decorative, automotive interiortrim part or article constructed in accordance with at least oneembodiment of the present invention;

FIG. 3A is a sectional view of the part of FIG. 2 taken along lines 3-3of FIG. 2 ;

FIG. 3B is an enlarged view of a portion of the part of FIG. 3A takenwithin a dashed box labeled 3B;

FIG. 3C is a rear perspective view, partially broken away, of the partof FIG. 2 after injection molding;

FIG. 4 is a side schematic view illustrating an automated manufacturingmethod and system of at least one embodiment of the present inventionfor making parts such as the part of FIGS. 1-3C; and

FIG. 5 is a view, similar to the view of FIG. 4 , but illustrating adifferent embodiment of the method and system.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

In general, at least one embodiment of the present invention deals withthe development of an automated method of and system for compressionmolding plastic sheet material with an in-mold coating 8 to form anin-mold coated plastic article, generally indicated at 10. The sheetmaterial may be porous, fiber-reinforced thermoplastic sheet material.The method of the at least one embodiment allows one to compression moldheated blanks 9 (FIGS. 4 and 5 ) of moldable, plastic sheet materialwith a cost and cycle time that can be used for automotive and otherhigh volume applications. The method of the present invention requiresonly a single stamping step or stage.

The composite thermoplastic sheet material preferably comprises aplurality of discontinuous or continuous fibers dispersed within athermoplastic resin. The thermoplastic resin is preferably selected frompolyolefins, thermoplastic polyolefin blends, polyvinyl polymers, dienepolymers, polyamides, polyesters, polycarbonates, polyestercarbonates,styrene-containing polymers, acrylic polymers, polyimides,polylphenylene ether, polyphenylene oxide, polyphenylene sulphide,polyethers, polyetherketones, polyacetals, polyurethanes,polybenzimidazole, and copolymers or mixtures thereof.

The fibers are preferably selected from glass fibers, carbon fibers,synthetic organic fibers, natural fibers, mineral fibers, metal and/ormetalized or coated fibers, or mixtures thereof. The fibers may beselected from polyaramid fibers, polyester fibers, nylon fibers, hempfibers, sisal fibers, basalt fibers, steel fibers, aluminum fibers,copper fibers, zinc fibers, or mixtures thereof.

The composite sheet material preferably has a porosity between about 5%to about 95% by volume and an areal density of from about 400 g/m² toabout 4000 g/m². The fiber content is preferably from about 20% to about80% by weight of the thermoplastic resin.

At least one embodiment of the present invention provides a method ofand system for making a laminated trim component, such as vehicle,interior trim component, generally indicated at 10 in FIG. 2 . Exemplarylocations for such articles are indicated in FIG. 1 by arrows 100. Thearticle 10 has an outer “A” surface 12 (FIGS. 2 and 3B) and an inner “B”surface 14 (FIG. 3A). The “A” surface 12 may be textured as indicated inFIG. 2 to look like a grained, injection molded part. Examples of suchtextures include a “wood grain” texture 11, a leather grain texture 13,a carbon fiber texture 15, a natural fiber texture 19 and a texture 21which provides a “logo” or other desired decorative design. As is wellknown in the art, the texture of the in-mold, coating 8 is typicallyprovided by the surfaces of the article-defining cavity (62, 62′) of afemale die (60, 60′) of a molding machine.

Referring specifically to FIGS. 3A and 3B, during the above-notedcompression molding process, the thermoplastic which serves as a matrixto the fibers forms an adhesive layer 7 to chemically bond the substrate6 (i.e. the blank 9) to the coating 8 formed from the in-mold coatingcomposition. The heat and pressure in the article-defining cavity (62,62′) causes the thermoplastic to migrate through the fibers so that theconcentration of the thermoplastic is greater at the interface betweenthe coating 8 and the substrate 6 than the concentration of thethermoplastic at other locations in the substrate 6 as indicated by therelative “darkness” of the adhesive layer 7 compared to the “darkness”of the rest of the substrate 6.

Referring now to FIG. 3C, the article 10 may also include a plurality ofcomponents which are made from plastic resin which initially flows frominjection molding “drops” 30 to form stiffening ribs 32, receptacles 34and posts 36 to provide attachment locations for various automotivecomponents including wiring harnesses, etc. on the “B” surface 14 of thearticle 10.

A system constructed in accordance with two embodiments of the presentinvention is generally indicated at 20 and 20′ in FIGS. 4 and 5 ,respectively. The parts or components of the system 20′ which are thesame or similar to the parts or components of the system 20 in eitherstructure or function have a single prime designation.

The system 10 includes a plurality of program-controlled manipulators orrobots 22, 24, 26 and 28. The robots 22 and 24 have the ability to pickup unheated and heated blanks 9 within a specified range of allowableblanks using multiple, end-of-arm, tooling or grippers 41. The robots 22and 24 pick up and orient the unheated and heated blanks, respectively,at load, heating and molding stations 43, 45 and 47, respectively.

The robot 26 has an automatic sprayer 42 for spraying an in-mold coatingcomposition, for example, one provided by Red Spot Paint and Varnish Co.Inc. of Evansville, Ind. The robot 28 has an end-of-arm tooling or endeffector 49 to pick up a finished article 10 at the molding station 47and place the finished article 10 on a conveyor 51.

The robots 20, 24, 26 and 28 are preferably multi-axis robots and arepreferably vision-guided by cameras (not shown) located on or adjacentthe robots. The robot 22 may be vision-guided to identify, pick, orient,and present the blanks 9 “bottom down” so that they are supported on abelt 53 within an oil-heated oven 55 at the heating station 45. Thegrippers 41 and 49 accommodate multiple blank and part families,respectively.

Benefits of Vision-based Robot Automation include but are not limited tothe following:

Smooth motion in high speed applications;

Handles multiple blanks and parts;

Slim designs to operate in narrow spaces;

Integrated vision; and

Dual end-of-arm tooling or grippers 41 and 49 designed to handlemultiple blank and part families.

A master control station or system controller (not shown) determineslocations and orientations of the blanks 9 of moldable plastic sheetmaterials, heated blanks, and finished articles 10, using any suitablemachine vision system having at least one camera. Any one or more ofvarious arrangements of vision systems may be used for providing visualinformation from image processors to the master controller. The visionsystem may include three-dimensional stationary cameras or robot-mountedcameras that provide light over fields of vision or view, creating astripe of light (or other pattern) across the blanks or finishedarticles as they pass under the cameras. In various embodiments, thelight may be a laser beam. The cameras, their image processors and themaster controller may be configured to locate various features such asholes. Alternatively, or in addition, the master controller may registerthe contours of the finished article 10 based on the various depths ofthe light on the surfaces of the article 10.

In some embodiments, multiple cameras can be situated at fixed locationson a frame structure (not shown) at the stations 43, 45 and 47 or may bemounted on the arms of the robots 22, 24, 26 and 28. Cameras may bespaced apart from one another on the frame structure. The cameras aretypically operatively connected to the master controller via theirrespective image processors. The master controller also controls therobots 22, 24, 26 and 28 of the system 10 through their respective robotcontrollers (not shown). Based on the information received from thecameras, the master controller then provides control signals to therobot controllers that actuate robotic arm(s) of the robots 22, 24, 26and 28 used in the system 10.

The master controller at the master control station can include aprocessor and a memory on which is recorded instructions or code forcommunicating with the robot controllers, the vision systems, therobotic system sensor(s), etc. The master controller is configured toexecute the instructions from its memory, via its processor. Forexample, the master controller can be a host machine or distributedsystem, e.g., a computer such as a digital computer or microcomputer,acting as a control module having a processor and, as the memory,tangible, non-transitory computer-readable memory such as read-onlymemory (ROM) or flash memory. The master controller can also have randomaccess memory (RAM), electrically-erasable, programmable, read onlymemory (EEPROM), a high-speed clock, analog-to-digital (A/D) and/ordigital-to-analog (D/A) circuitry, and any required input/outputcircuitry and associated devices, as well as any required signalconditioning and/or signal buffering circuitry. Therefore, the mastercontroller can include all software, hardware, memory, algorithms,connections, sensors, etc., necessary to monitor and control the visionsubsystem, the robotic subsystem, etc. As such, a control method can beembodied as software or firmware associated with the master controller.It is to be appreciated that the master controller can also include anydevice capable of analyzing data from various sensors, comparing data,making the necessary decisions required to control and monitor thevision subsystem, the robotic subsystem, sensors. etc.

An end effector on each robot arm of the robots 22, 24 and 28 mayinclude a series of grippers supported to pick up the heated andun-heated blanks as well as the finished articles. The robotic arm isthen actuated by its controller to pick up the heated or un-heated blankor the finished article with the particular gripper. The robot arm ofthe robot 28 puts the finished parts 10 on the conveyor 51 afterpositioning its gripper 49 relative to the article 10 using thedetermined location from the visual position data of the particularvision subsystem including its camera and image processor.

The composite blank or sheet 9 is heated in the oven 55 while on thebelt 57 to a first softening temperature. The composite sheet 9 isstretchable when heated to the first softening temperature.

As shown in FIG. 4 , the system 10 also includes a female die, generallyindicated at 60, having an article-defining cavity 62 defined by innersurfaces of the female die 60. The female die 60 is typically positionedon a lower base member of a press (not shown). The system 10 alsoincludes a male die, generally indicated at 64, typically mounted on amovable member of the press for forcing an inner portion of a heatedblank 9 of thermoplastic material into the female die 60 in a directionalong a substantially vertical axis and against the previously sprayedin-mold material. The stamping press including the upper moveable memberforces the male die 64 including protrusions 66, into the female die 60which is supported on the lower base member of the stamping press.

In the embodiment of FIG. 5 , the positions and movements of the maledie 64′ and the female die 62′ are reversed for the reasons noted below.

In one embodiment of the present invention, the method includes placingor positioning a previously heated (in a range of approximately 320° F.to approximately 570° F.) blank 9 of moldable, composite plastic sheetmaterial over the cavity 62 of the female die 60. If the plastic ispolypropylene, the temperature may be approximately 400° F. The blank 9has a predefined position and orientation over the cavity 62. Outerperipheral portions of the blank 9 may be perforated at holes (notshown) to enable the blank 9 to be held at posts (not shown) whichextend upwardly through the holes from the outer surface of the femaledie 60. The posts are removably positioned on the upper surface of thefemale die 60 to form different patterns or clusters of posts dependingon the size and shape of the desired article. In this way, the holdingforces at the outer peripheral portions of the heated blank 9 can bevaried so that the heated blank 9 stretches but does not wrinkle, tearor rip during a deep-drawn compression molding process. Also,spring-loaded angled clamps (not shown) extend upwardly from the uppersurface of the female die 60 to controllably hold outer peripheralportions of the blank 9. The posts and the clamps may be removable orretractable to vary the positions and/or locations at which the outerperipheral portions of the blank 9 are held based on the size and shapeof the formed article 10.

The inner portion of the heated blank 9 is forced into the cavity 62 ofthe female die 60 along the substantially vertical axis and against thenow dry, in-mold coating composition or material which had previouslybeen sprayed on the inner surfaces of the female die 60 by the robot 26.The outer portions of the heated blank 9 adjacent the cavity 62 are heldby the posts and clamps to resist movement of the outer portions towardsthe article-defining cavity 62 during the step of forcing so that thedeep-drawn material controllably stretches but does not wrinkle, rip ortear during the step of forcing.

Then the male die 60 is retracted in the opposite direction along thevertical axis, and the deep-drawn article is removed from the female die60 by the robot 28 and any excess material (which typically includes theholes) from the periphery of the deep-drawn article 10 is also removed.

As shown in FIG. 5 , the lower mold half 64′ may include passages 80′for molding a plastic injected by a nozzle 82′ into the lower mold half64′. The plastic is compatible with the plastic of the composite blankor sheet 9 to bond the plastics together and to form the at least onecomponent such as the components 32, 34 and 36 at the inner surface 14of the composite sheet 9 (FIG. 3C) at the molding station 47′.Alternatively, as shown in FIG. 4 , the upper mold half 64 may have thepassages 80 for molding a plastic injected by a nozzle 82.

Also, a robot such as the robot 28 is not shown in FIG. 5 for the sakeof simplicity. Rather, only its end effector 49′ is shown.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. An automated method of manufacturing a coatedplastic article, the method comprising the steps of: providing a moldfor making the article, the mold having upper and lower mold halveswherein one of the mold halves has a mold surface which at leastpartially defines an article-defining cavity; coating at least a portionof the mold surface with an in-mold coating composition; placing aheated blank of moldable plastic sheet material between the upper andlower mold halves, the blank having inner and outer surfaces wherein theplastic sheet material comprises a plastic resin; forcing an innerportion of the heated blank into the article-defining cavity so that theouter surface of the blank is in contact with at least a portion of thein-mold coating composition; causing the in-mold coating composition tocure to form a coating and causing plastic resin of the inner portion ofthe blank to form an adhesive layer which chemically bonds the blank tothe coating; and molding a plastic compatible with the plastic resin ofthe sheet to form at least one component on the inner surface of thesheet and so as to form the coated plastic article and wherein thearticle is a laminated article molded as a unitary structure.
 2. Themethod as claimed in claim 1, wherein the plastic sheet material is acomposite plastic sheet material.
 3. The method as claimed in claim 1,wherein the coating has a textured, class “A” surface.
 4. The method asclaimed in claim 1, wherein the step of forcing is performed in a singlestamping stage.
 5. The method as claimed in claim 2, wherein thecomposite plastic sheet material comprises a plurality of fibersdispersed within a thermoplastic resin.
 6. The method as claimed inclaim 5, wherein the thermoplastic resin is selected from polyolefins,thermoplastic polyolefin blends, polyvinyl polymers, diene polymers,polyamides, polyesters, polycarbonates, polyestercarbonates,styrene-containing polymers, acrylic polymers, polyimides,polylphenylene either, polyphenylene oxide, polyphenylenesulphide,polyethers, polyetherketones, polyacetals, polyurethanes,polybenzimidazole, and copolymers or mixtures thereof.
 7. The method asclaimed in claim 5, wherein the fibers are selected from glass fibers,carbon fibers, synthetic organic fibers, natural fibers, mineral fibers,metal and/or metalized or coated fibers, or mixtures thereof.
 8. Themethod as claimed in claim 1, wherein the article is a decorativeautomotive interior trim article.
 9. The method as claimed in claim 5,wherein the fiber content is from about 20% to about 80% by weight ofthe thermoplastic resin.
 10. The method as claimed in claim 1, whereinthe article has a thickness in a range of 1 mm to 10 mm.